Processing of laundry is, in this disclosure, defined as any action performed on laundry so as to change the properties of the laundry itself, e.g. soaking, dissolving and removal of dirt, removal of water and/or detergent from the laundry, changing the compactness or level of creasing of the laundry, etc. Some laundry processing devices, e.g. washing machines, tumble dryers and combined washing machines/dryers, generally operate by processing the laundry in a rotatable drum. The drum is rotated according to a particular program, which can be selected by the user. Typically, a washing machine following a washing program performs a number of functions, including soaking, washing, rinsing, spin-drying, and detachment/de-compacting, each function having its own process parameters with respect to washing fluid level, concentration and type of detergent, washing fluid temperature, rotary speed of the drum etc. The washing fluid may be, for example, water or CO2 in liquid or supercritical phase. A tumble dryer normally follows a simpler program, merely rotating the drum and periodically changing its direction of rotation.
As there is a widespread and increasing awareness of environmental issues in society, there is a demand for more efficient laundry processing devices with respect to washing fluid, detergent and energy consumption. However, simply reducing the amount of washing fluid in a washing machine or shortening the operating time of a washing machine or a tumble dryer will merely result in the laundry not being properly cleaned, or dried, respectively. There is thus a strong need for more efficient laundry processing devices and methods.